The impact of motivation on listening effort: Effects of task demand and success importance on cardiovascular correlates of listening effort
In my talk, I will present an adaption of Brehm’s motivational intensity theory – a psychological theory that predicts effort mobilisation in instrumental tasks – to listening effort and cardiovascular correlates of listening effort. According to this theory, listening effort should be a direct function of listening demand: the more difficult the listening task, the higher the invested effort. However, this relationship between listening demand and listening effort should be limited by success importance and only hold if listening demand is fixed. If success importance does not justify the required listening effort, individuals should disengage and not invest any effort. If listening demand is unclear or unfixed, success importance should be the direct determinant of listening effort: the higher the success importance, the higher the invested effort.
I will present three studies that tested these predictions using cardiovascular indicators of effort. Study 1 examined the impact of listening demand on effort-related cardiovascular activity manipulating the difficulty of a speech-in-noise task across four levels. Study 2 varied both task demand and success importance of an auditory discrimination task to examine the joint impact of both variables on listening effort. Study 3 tested the predicted effect of success importance on effort-related cardiovascular activity in a speech-in-noise task with unclear demand. The results of all three studies corroborated the predictions of motivational intensity theory demonstrating that it is important to consider motivational variables beyond task demand in the research on listening effort.